Toll-like receptors (TLRs) play crucial roles in host immune defenses. Recently, TLR-mediated autophagy is reported to promote immune responses via increasing antigen processing and presentation in antigen presenting cells. The present study examined whether the synthetic TLR4 activator (CCL-34) could induce autophagy to promote innate and adaptive immunity. In addition, the potential of CCL-34 as an immune adjuvant in vivo was also investigated. Our data using RAW264.7 cells and bone marrow-derived macrophages showed that CCL-34 induced autophagy through a TLR4-NF-κB pathway. The autophagy-related molecules (Nrf2, p62 and Beclin 1) were activated in RAW264.7 cells and bone marrow-derived macrophages under CCL-34 treatment. CCL-34-stimulated macrophages exhibited significant antigen-processing activity and induced the proliferation of antigen-specific CD4+T cells as well as the production of activated T cell-related cytokines, IL-2 and IFN-γ. Furthermore, CCL-34 immunization in mice induced infiltration of monocytes in the peritoneal cavity and elevation of antigen-specific IgG in the serum. CCL-34 treatment in vivo did not cause toxicity based on serum biochemical profiles. Notably, the antigen-specific responses induced by CCL-34 were attenuated by the autophagy inhibitor, 3-methyladenine. In summary, we demonstrated CCL-34 can induce autophagy to promote antigen-specific immune responses and act as an efficient adjuvant. Vaccine development holds a great contribution in infectious disease prevention and cancer immunotherapy. Vaccines contain both antigens and adjuvants to induce antigen (Ag)-specific antibody responses. Adjuvants are required to boost Ag-specific adaptive immune response in B cells and T cells. The current strategies of vaccine development to trigger early immune responses are via enhancing Ag uptake in antigen-presenting cells (APCs), providing appropriate microenvironments for APC activations, and further promoting the differentiation of naïve T cells into effector T cells 1,2. Currently licensed adjuvants in clinical applications, such as AS04, MF59 and Alum, were reported to activate pattern recognition receptors (PRRs) and/or NLRP3 inflammasome, which trigger humoral antibody responses accompanied with T cell responses 1,3-5. Recent studies showed that stimulation of autophagy is able to augment T cell responses via modulating the functions in both APCs and T cells 6. The autophagy/lysosome degradation pathway is an evolutionarily conserved stress response mechanism for survival 7 , and its dysregulation plays critical roles in human diseases 8. During infection, one of the major immune mechanisms against pathogens is to induce canonical and noncanonical autophagy in macrophages. The canonical selective autophagy (xenophagy) selectively captures and degrades intracellular mycobacteria, such as Mycobacterium tuberculosis and Listeria monocytogenes 9,10. Moreover, the noncanonical autophagy, LC3-associated phagocytosis (LAP), can accelerate pathogen clearance 11-15. Furthermore, induction o...

No abstract

BackgroundComplementary therapies are widely used among cancer patients. Kuan-Sin-Yin (KSY) decoction, a popular qi-promoting herbal medicine, was constituted with several herbs known to exhibit immunomodulating or anticancer activity. After combining these herbs as a compound formula, it is necessary to reassess the immunomodulation effects, the effects on tumor growth, and possible toxicity of KSY.MethodsThe anti-cancer effects of KSY in vivo were determined by measuring the tumor volumes, anticancer-associated cytokines (IFN-gamma, TNF-alpha, IL-2, and IL-12), accumulation of tumor infiltrating leukocytes (TILs), proliferation and apoptosis-related molecular markers (Ki-67, p53, p21, activated caspase 3, and cleaved PARP), and an in situ TUNEL assay. The body weight and serum chemistry of treated mice were also assessed. In vitro, the effects of KSY were evaluated using MTT assay, BrdU incorporation assay and cell growth curve.ResultsIn vivo, KSY suppressed bladder or lung cancer growth but did not promote the production of cytokines nor increase the accumulation of TILs. The expression of p53 and p21 in KSY-treated mice were increased. The numbers of apoptotic tumor cells and the expression of apoptosis marker proteins (Caspase 3 and cleaved PARP) were not significantly elevated after KSY treatment. In vitro, the viability and proliferation of tumor cells, but not normal cells, were suppressed by KSY treatment. No significant toxicity was found in KSY-treated mice.ConclusionsKSY suppressed the tumor growth in vivo and in vitro, which resulted from its cytostatic effects on cancer cells, rather than the induction of anti-cancer immunity. Under these experimental conditions, no apparent toxicity was observed.Electronic supplementary materialThe online version of this article (doi:10.1186/1472-6882-14-488) contains supplementary material, which is available to authorized users.

No abstract

No abstract